Easy Rainbow Cake

This rainbow cake was made for a birthday a few years ago and the only camera I had was a little smartphone so the photography isn’t great. The method was easier than I expected and the kids loved it!

I used a white chocolate mud cake recipe that I modified (you will find it below). When I made it I joined the layers with icing from a tub because I had a steady supply of it for free. Now I would use either cream, a buttercream icing mixture or chocolate ganache. I made the following recipe twice to make enough layers. I only had a microwave at the time to use as well, which is another reason I chose mudcake – less chance of a dry microwave cake with a mudcake.

Method
1.) Heat the butter and white chocolate over low heat to melt. This can be done either in 30 second bursts in the microwave in a microwave proof dish or use a saucepan. To melt chocolate this way place water in the saucepan and place a glass bowl over the saucepan. Boil the water, place the chocolate and butter in the bowl and melt, stirring every now and then to ensure it is even.
2.) In a bowl, combine the sugar and milk with the melted butter and chocolate until the sugar has dissolved. I did this gently by hand.
3.) In a separate bowl, sift the flours together then sift them into the chocolate mixture, stirring gently as you do.
4.) Stir in the eggs, sour cream and vanilla essence. Mix well to combine.
5.) Divide the mixture into 3 bowls. Add food colouring of your desired colour to each e.g pink in one, blue in another and yellow in another.
6.) Pour the mixtures into separate microwave safe cake containers (I used a Tupperware Stack cooker and cooked 2 cakes at once). Alternatively, place them in cake tins and bake in a moderate oven.
7.) Cook on high for 10 minutes in the microwave or in a moderate overn for 30 minutes (or until cooked through).
8.) Leave to cool for a few minutes then turn it out onto a rack to cool.
9.) Repeat the process with all the mixture and each colour you need.
10.) Once the cakes have cooled completely, get ready to layer and ice them. Select the order of the colours. I started with purple. Place your first colour on the bottom of the tray you wish to serve from.
11.) Cover the top of this layer with a layer of icing. Repeat with each layer. I went purple cake then icing layer followed by blue cake layer, more icing, green cake layer with more icing etc. Finishing with pink.
12.) Whip the cream until firm, then mix in the icing sugar.
13.) Cover the cake in whipped cream.
14.) Before serving decorate as you wish. I used smarties but they slid off a little because it was iced with cream. I recommend grated chocolate or sprinkles instead.

Notes:
I did my colours as follows –
Pink was ½ the bottle of red food dye
Orange was about 10 drops of yellow and 5 drops of red
Yellow was about ¼ of the yellow food dye bottle
Green was about ¼ of the green bottle
Blue was about ¼ blue bottle
Purple was about 16 drops of red to 8 drops of blue